Add loops to validate data. Add a menu to your program that allows users to use the various features or exit the program.

Examples: In the programming tutorial, add a tutorial on working with loops. Then use loops to validate user input and display an error message if they enter data outside the valid range. Use a main loop to allow the user to keep selecting different tutorials until they decide to exit the program. I need help with this C++ course project. I already have a menu in my program, so I just need to make an option 4 to my menu using the loops to validata data. You can add an exit program too in my menu. Thanks in advanced!

Here is my code:

#include "stdafx.h"

#include

#include

using namespace std;

int nMonths = 0;

float loanAmount;

float totalPaid = 0.0f;

void process() {

float interestRate;

float monthlyPayment;

cout << "What is the amount of the loan?:$";

cin >> loanAmount; cin.ignore();

cout << "What is the interest rate on the loan?:$";

cin >> interestRate; interestRate /= 100; cin.ignore();

cout << "What is the desired monthly payment?:$";

cin >> monthlyPayment; cin.ignore();

while (monthlyPayment < loanAmount * interestRate / 12) {

cout << "Not a valid amount, Amount must be greater than $";

cout << (loanAmount * interestRate / 12) << endl;

cout << "What is the desired monthly payment amount? $";

cin >> monthlyPayment; cin.ignore();

}

float interestToAdd = 0.0f;

float remaining = loanAmount;

float toAdd = 0.0f;

cout << endl;

cout << "Month" << " (Interest Added)" << " (Amount Paid)" << " (Debt Remaining)" << endl;

while (remaining > monthlyPayment) {

interestToAdd = remaining * interestRate / 12;

nMonths++;

remaining += interestToAdd;

if (remaining > monthlyPayment) {

toAdd = monthlyPayment;

}

else {

toAdd = remaining;

}

cout << nMonths << " $" << interestToAdd << " $" << toAdd

<< " $" << remaining << endl;

totalPaid += toAdd;

remaining -= toAdd;

}

}

void displayResult() {

cout << endl << "Statistics about loan. " << endl;

cout << "Initial loan amount: $" << loanAmount << endl;

cout << "Total amount paid: $" << totalPaid << endl;

cout << "Time to pay off loan: " << nMonths << endl;

cout << "Overpay percentage: " << (totalPaid / loanAmount) << endl;

cin.ignore();

}

void chooseletterA() {

float Amount, rateOfIntrest, monthlyAmountToPay, totalAmount;

int lengthOfLoan;

cout << "What is the amount of the loan?:$";

cin >> Amount;

cin.ignore();

cout << "What is the interest rate on the loan?";

cin >> rateOfIntrest;

rateOfIntrest /= 100;

cin.ignore();

cout << "What is the length of loan?:$";

cin >> lengthOfLoan;

monthlyAmountToPay = (Amount*rateOfIntrest*pow((1 + rateOfIntrest), lengthOfLoan)) / (pow((1 + rateOfIntrest), lengthOfLoan - 1));

cout << "Your monthly loan payment amount = $" << monthlyAmountToPay << endl;

system("pause");

}

void chooseletterB() {

float Amount, rateOfIntrest, monthlyAmountToPay, totalAmount;

int lengthOfLoan;

cout << "What is the monthly amount of the loan?:$";

cin >> monthlyAmountToPay;

cin.ignore();

cout << "What is the interest rate on the loan?";

cin >> rateOfIntrest;

rateOfIntrest /= 100;

cin.ignore();

cout << "What is the length of loan?:$";

cin >> lengthOfLoan;

cin.ignore();

Amount = monthlyAmountToPay * pow((1 + rateOfIntrest), lengthOfLoan - 1) / (rateOfIntrest*pow((1 + rateOfIntrest), lengthOfLoan));

cout << "Your total loan amount = $" << Amount << endl;

system("pause");

}

void chooseletterC() {

float Amount, rateOfIntrest, monthlyAmountToPay, totalAmount;

int lengthOfLoan;

cout << "What is the amount of the loan?:$";

cin >> Amount;

cin.ignore();

cout << "What is the monthly amount of the loan?:$";

cin >> monthlyAmountToPay;

cin.ignore();

cout << "What is the length of loan?:$";

cin >> lengthOfLoan;

cin.ignore();

rateOfIntrest = ((monthlyAmountToPay *lengthOfLoan) - Amount) / lengthOfLoan;

cout << "Your monthly monthly rate of intrest = $" << rateOfIntrest / 12 << endl;

system("pause");

}

void chooseletterD() {

float Amount, rateOfIntrest, monthlyAmountToPay, totalAmount;

int lengthOfLoan;

cout << "What is the amount of the loan?:$";

cin >> Amount;

cin.ignore();

cout << "What is the monthly amount of the loan?:$";

cin >> monthlyAmountToPay;

cin.ignore();

cout << "What is the interest rate on the loan?";

cin >> rateOfIntrest;

rateOfIntrest /= 100;

cin.ignore();

lengthOfLoan = (log(Amount) - log(monthlyAmountToPay)) / (log(1 + rateOfIntrest));

cout << "Your length of loan amount = $" << lengthOfLoan << endl;

system("pause");

}

void multipleChoice() {

cout << "Welcome to the multiple choice part of the program, please choose a letter: " << endl;

cout << "A: Monthly payment " << endl;

cout << "B: Loan amount " << endl;

cout << "C: Length of loan " << endl;

cout << "D: Interest rate " << endl;

char ch;

cin >> ch;

switch (ch)

{

case 'A':

chooseletterA();

cout << "First question: Please solve for monthly payment. " << endl;

break;

case 'B':

chooseletterB();

cout << "Second question: Please solve for loan amount. " << endl;

break;

case 'C':

chooseletterC();

cout << "Third question: Please solve for length of loan. " << endl;

break;

case 'D':

chooseletterD();

cout << "Forth question: Please solve for interest rate. " << endl;

break;

}

}

int main() {

int ch;

do {

cout << endl << "************************MENU***************************" << endl;

cout << "1. Process Loan" << endl;

cout << "2. Display Result" << endl;

cout << "3. Multiple Choice" << endl;

cout << "Enter your choice : ";

cin >> ch;

switch (ch) {

case 1:

process();

break;

case 2:

displayResult();

break;

case 3:

multipleChoice();

break;

default:

cout << "Entered Wrong Keyword.... Re-enter Again";

break;

}

} while (ch<3 && ch> 0);

return 0;

}